There is no form to upload an avatar for a group?

I’m going through and testing functions.
Step 1. I start a group
Step 2. I choose whether or not the group is public, private or hidden.
Step 3. I get to choose an avatar – but there is no form to upload the avatar, just a previous and next button.
Step 4. I get to invite people.
Create the group – the default Mystery Man avatar is used.

There doesn’t seem to be a way to edit the avatar.

If I’m going to use avatars, I’d like to be able to upload it on Step 3.